In “Saturday Night Live’s” last two seasons, one of the best recurring bits has been Nasim Pedrad as Bedelia, the teenaged girl who’s a little too eager to be best buddies with her slightly puzzled parents.

You know sweet, fictional Bedelia would have to be a hardcore Gleek — and you imagine her rushing home to share the latest “Glee” soundtrack with her BFF-folks.

“Hey, mom and dad!” she’d enthuse. “Now I really get why you were so into Queen, Rick Springfield and ‘Retha! And I know you’re going to love these Katy Perry and Pink covers! Did you know Lea Michele is a dead ringer for Streisand? It’s a crime she’s not doing the ‘Funny Girl’ revival.”

Surreptitious eye-rolling and a whole-family sing-along to “Safety Dance” would ensue.

This putative closing of the pop generation gap has been a bright spot for the music business. In just a couple of seasons, “Glee” has birthed eight full-length soundtrack albums so far (not counting several EPs), and they’ve all debuted in the Billboard/SoundScan top five.

There’s no reason to expect any less a bow for the ninth official cast album, “Glee the 3D Concert Movie: Motion Picture Soundtrack,” which is essentially a best-of for the previous releases, with the addition of an arena’s worth of applause each time an unseen character walks (or, in Artie’s case, rolls) onto the stage.

“Glee” albums are by now as reliable a product line as the Kidz Bop collections, to which they bear a closer kinship than enthusiasts might like to admit. Parents of a certain age might also think back to an earlier franchise: the “Stars on 45” medleys of the late 1970s.

The hits being covered here from the distant past and near-present aren’t quite being condensed down into medleys, but it can start to feel like it, the way most of the tunes have been abridged to last just 2-3 minutes. The “Glee 3D” soundtrack sports 23 tracks but clocks in at just over an hour — the kind of brisk accomplishment that’s possible when you cut a minute out of “Firework” here and a minute out of “Jessie’s Girl” there.

Transitions are presumably edited a good deal tighter than they occurred when the “Glee” cast went on tour earlier this summer. There’s an abruptness to the way the “Puck” performance of “Fat Bottomed Girls” leads directly into the “Kurt” rendition of “I Want to Hold Your Hand.” But maybe we’re meant to ponder the immediate juxtaposition of straight debauchery and gay innocence.

Chris Colfer’s wistful, balladic take on the latter Beatles classic is the most original arrangement on the album — original, that is, if you’ve never seen or heard the version from Julie Taymor’s “Across the Universe” that’s being copied. Even the context is markedly unoriginal, as the Taymor useage marked already reestablished the Fabs’ teen crush tune as an anthem of gay longing (although, in that film, it was sung by an actress, and one with a lower voice than Colfer’s).

For the most part, there’s a whole lotta apin’ goin’ on, with no cultural middleman involved as the arrangers go right back to the source. Which sometimes is a very recent one. Does anyone really need to hear Michele out-Perry Katy Perry on “Firework,” or Naya Rivera do a straight-up Amy Winehouse impression on “Valerie”?

The scariest copycatting comes when Colfer and Michele trot out their respective impressions of Judy Garland and Babs for a duet of the divas’ legendary 1963 mash-up of “Get Happy” and “Happy Days Are Here Again.” That’s later followed by Michele’s show-stopping solo take on “Don’t Rain on My Parade,” a hilariously overenuniciated homage to the original Funny Girl that’s meant to leave you exclaiming “I can’t believe it’s not buttah!”

Horror and admiration both seem like appropriate responses to such accomplished, if exaggerated, mimicry.

Actually, there is one moment where the album makes a serious break from the source material. That’s in handing “I’m a Slave 4 U” to someone (Heather Morris) who can sing. But it turns out that particular tune is a little better being delivered soullessly and robotically.

If you’ve spent the last 25 years longing for a version of “Silly Love Songs” that didn’t have so much doggoned edge to it, “Glee the 3D Movie” is your album. But not everything seems quite as pointless as having the New Directions boy chorale smooth out Wings’ rough edges. The franchise is at its best in occasional moments of tackling recent or lesser-known rockers that hardly seemed ripe to become show tunes, like Florence and the Machine’s “Dog Days Are Over.”

Anyway, there’s no way to avoid seeming churlish when you’re taking shots at a pop phenomenon meant to bring generations together in the appreciation of song. If Norman Rockwell’s iconic painting of the family supper had a contemporary soundtrack, surely every last airbrushed family member would be singing, “Left alone with big fat Fanny/She was such a naughty nanny!”

Chris Willman has been a frequent contributor to TV Guide, New York magazine, the Los Angeles Times, Rolling Stone, Spin, Billboard, Parade and other publications. In a long run at Entertainment Weekly, he penned more than 20 cover stories as a senior writer before becoming the magazine’s chief music critic. His book "Rednecks & Bluenecks: The Politics of Country Music" was praised by Stephen King, who said, “You won’t read a better book about American music this year — or, probably, a better one about American political thought.”